Hey all, so I'm going to get the new iMac with Retina display and I wanted to know what your thoughts are regarding the two available GPUs: The AMD R9 M290X w/ 2GB GDDR5, or, for $250 more, the R9 M295X w/ 4GB GDDR5. Isn't the GPU taxed a lot with having to drive all those beautiful (and now invisible) pixels? I don't use Adobe or edit video at all and I'm not much of a gamer either. Will the M295X makes everything "smoother", if you will. Your thoughts?